The quantity of data used in a computer system has increased rapidly in recent years. As a storage system for managing such data, a large-scale storage system combined with a file system and managed by a RAID (Redundant Arrays of Inexpensive Disks) method for providing huge storage resources as called mid-range class or enterprise class has attracted public attention recently. To use and manage such huge data efficiently, there has been developed a technique for connecting a storage system such as a disk array system to information processors by a private network (Storage Area Network, hereinafter referred to as SAN) to thereby achieve high-speed and large-volume access to the storage system. On the other hand, a storage system called NAS (Network Attached Storage) has been developed so that the storage system is connected to each information processor through a network using a protocol such as TCP/IP (Transmission Control Protocol/Internet Protocol) to achieve access at file level from the information processor. In such a storage system, license setting (registration) is generally required for validating an operating system or application program installed in a computer for the purpose of preventing illegal copy. When the number of programs installed is large or when the number of computers to be managed is large, the number of licenses to be managed increases inevitably. As a system for managing such licenses, there is known a system for re-registering licenses for installation programs used by changed staffs of a corporation or group, for example, in altering the organization or personnel changes in the corporation or group (e.g., JP-A-2002-279165).